/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you under the Apache License, Version 2.0 (the
 *  "License"); you may not use this file except in compliance
 *  with the License.  You may obtain a copy of the License at
 *  
 *    http://www.apache.org/licenses/LICENSE-2.0
 *  
 *  Unless required by applicable law or agreed to in writing,
 *  software distributed under the License is distributed on an
 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 *  KIND, either express or implied.  See the License for the
 *  specific language governing permissions and limitations
 *  under the License. 
 *  
 */
package org.apache.mina.common.support;

import java.lang.reflect.Method;

import org.apache.mina.common.DefaultIoFilterChainBuilder;
import org.apache.mina.common.ExecutorThreadModel;
import org.apache.mina.common.IoFilterChainBuilder;
import org.apache.mina.common.IoServiceConfig;
import org.apache.mina.common.ThreadModel;

/**
 * A base implementation of {@link IoServiceConfig}.
 * 
 * @author The Apache Directory Project (mina-dev@directory.apache.org)
 * @version $Rev$, $Date$
 */
public abstract class BaseIoServiceConfig implements IoServiceConfig, Cloneable {
    /**
     * Current filter chain builder.
     */
    private IoFilterChainBuilder filterChainBuilder = new DefaultIoFilterChainBuilder();

    /**
     * The default thread model (initialized lazily).
     */
    private ThreadModel defaultThreadModel;

    /**
     * Current thread model.
     */
    private ThreadModel threadModel;

    public BaseIoServiceConfig() {
        super();
    }

    public IoFilterChainBuilder getFilterChainBuilder() {
        return filterChainBuilder;
    }

    public void setFilterChainBuilder(IoFilterChainBuilder builder) {
        if (builder == null) {
            builder = new DefaultIoFilterChainBuilder();
        }
        filterChainBuilder = builder;
    }

    public DefaultIoFilterChainBuilder getFilterChain() {
        if (filterChainBuilder instanceof DefaultIoFilterChainBuilder) {
            return (DefaultIoFilterChainBuilder) filterChainBuilder;
        } else {
            throw new IllegalStateException(
                    "Current filter chain builder is not a DefaultIoFilterChainBuilder.");
        }
    }

    public ThreadModel getThreadModel() {
        if (threadModel == null) {
            threadModel = getDefaultThreadModel();
        }
        return threadModel;
    }

    public void setThreadModel(ThreadModel threadModel) {
        if (threadModel == null) {
            // We reuse the previous default model to prevent too much
            // daemon threads are created.
            threadModel = getDefaultThreadModel();
        }
        this.threadModel = threadModel;
    }

    private synchronized ThreadModel getDefaultThreadModel() {
        if (defaultThreadModel == null) {
            defaultThreadModel = ExecutorThreadModel.getInstance("AnonymousIoService");
        }
        return defaultThreadModel;
    }

    public Object clone() {
        BaseIoServiceConfig ret;
        try {
            ret = (BaseIoServiceConfig) super.clone();
        } catch (CloneNotSupportedException e) {
            throw (InternalError) new InternalError().initCause(e);
        }

        // Try to clone the chain builder.
        try {
            Method cloneMethod = this.filterChainBuilder.getClass().getMethod(
                    "clone", null);
            if (cloneMethod.isAccessible()) {
                ret.filterChainBuilder = (IoFilterChainBuilder) cloneMethod
                        .invoke(this.filterChainBuilder, null);
            }
        } catch (Exception e) {
        }

        return ret;
    }
}
